/vr/ - Retro Games

>>3287754
>>3287771
Turn the red circled screw (trimmer capacitor) in pic related.
Just in case you happen to own a expensive and precise frequency counter then you should measure the frequency of the master clock.
It should be exactly 21.47727Mhz but if you're not able to make such precise measurements then adjust very slowly till you see color on your BVM.

>>3287853
Consoles and (old home) computers often have fine adjustments (trimmer capacitor) for their oscillators which the subcarrier frequency is derived from.
It is normal that when crystal oscillators age their frequency will change.
And sometimes it's so extreme that it needs to be replaced despite that the computer worked normally except that no TV showed color:
https://web.archive.org/web/20140906143156/http://www.pagetable.com/?p=672

>>3287916
No, purity adjustments are necessary which will may lead to need to adjust convergence and/or geometry as well.